diff --git a/src/lib_client_base/client_config.ml b/src/lib_client_base/client_config.ml
index 168d5ddcf..a2a484fe3 100644
--- a/src/lib_client_base/client_config.ml
+++ b/src/lib_client_base/client_config.ml
@@ -145,12 +145,14 @@ let protocol_parameter =
 let base_dir_arg =
   arg
     ~parameter:"-base-dir"
+    ~placeholder:"path"
     ~doc:("The directory where the Tezos client will store all its data. By default "
           ^ Client_commands.default_base_dir)
     string_parameter
 let config_file_arg =
   arg
     ~parameter:"-config-file"
+    ~placeholder:"path"
     ~doc:"The main configuration file."
     string_parameter
 let timings_switch =
@@ -160,12 +162,14 @@ let timings_switch =
 let block_arg =
   default_arg
     ~parameter:"-block"
+    ~placeholder:"hash|head|head~n"
     ~doc:"The block on which to apply contextual commands."
     ~default:(Block_services.to_string default_cli_args.block)
     block_parameter
 let protocol_arg =
   arg
     ~parameter:"-protocol"
+    ~placeholder:"hash"
     ~doc:"Use contextual commands of a specific protocol."
     protocol_parameter
 let log_requests_switch =
@@ -177,11 +181,13 @@ let log_requests_switch =
 let addr_arg =
   arg
     ~parameter:"-addr"
+    ~placeholder:"IP addr|host"
     ~doc:"The IP address of the node."
     string_parameter
 let port_arg =
   arg
     ~parameter:"-port"
+    ~placeholder:"number"
     ~doc:"The RPC port of the node."
     (parameter
        (fun _ x -> try
@@ -248,7 +254,8 @@ let commands config_file cfg =
     command ~group ~desc:"create a config file based on the current CLI values"
       (args1
          (default_arg
-            ~parameter:"-path"
+            ~parameter:"-file"
+            ~placeholder:"path"
             ~doc:"path at which to create the file"
             ~default:(cfg.base_dir // default_config_file_name)
             (parameter (fun _ctx str -> return str))))
diff --git a/src/lib_client_base/client_debug.ml b/src/lib_client_base/client_debug.ml
index 1f4cfc1b5..baa91e8fe 100644
--- a/src/lib_client_base/client_debug.ml
+++ b/src/lib_client_base/client_debug.ml
@@ -108,6 +108,7 @@ let commands () =
     arg
       ~doc:"Write output of debug command to file"
       ~parameter:"-file"
+      ~placeholder:"path"
     @@ parameter (fun _ str -> return str) in
   let output_to_ppf = function
     | None -> Format.std_formatter
diff --git a/src/lib_stdlib_lwt/cli_entries.ml b/src/lib_stdlib_lwt/cli_entries.ml
index ba4188890..d55912747 100644
--- a/src/lib_stdlib_lwt/cli_entries.ml
+++ b/src/lib_stdlib_lwt/cli_entries.ml
@@ -27,23 +27,27 @@ let parameter ?autocomplete converter =
 type ('a, 'ctx) arg =
   | Arg : { doc : string ;
             parameter : string ;
+            placeholder : string ;
             kind : ('p, 'ctx) parameter } ->
     ('p option, 'ctx) arg
   | DefArg : { doc : string ;
                parameter : string ;
+               placeholder : string ;
                kind : ('p, 'ctx) parameter ;
                default : string } -> ('p, 'ctx) arg
   | Switch : { doc : string ;
                parameter : string } ->
     (bool, 'ctx) arg
 
-let arg ~doc ~parameter kind =
+let arg ~doc ~parameter ~placeholder kind =
   Arg { doc ;
         parameter ;
+        placeholder ;
         kind }
 
-let default_arg ~doc ~parameter ~default kind =
+let default_arg ~doc ~parameter ~placeholder ~default kind =
   DefArg { doc ;
+           placeholder ;
            parameter ;
            kind ;
            default }
@@ -331,6 +335,7 @@ let rec help_commands commands =
             ~parameter:"-verbose")
          (default_arg
             ~doc:"Select the manual's output format"
+            ~placeholder: "plain|colors"
             ~parameter: "-format"
             ~default: (if Unix.isatty Unix.stdout then "colors" else "plain")
             (parameter
@@ -525,12 +530,12 @@ let trim s = (* config-file wokaround *)
 let print_options_detailed (type ctx) =
   let help_option : type a.Format.formatter -> (a, ctx) arg -> unit =
     fun ppf -> function
-      | Arg { parameter ; doc } ->
-          Format.fprintf ppf "@[<v 2>@{<opt>%s _@}:@,@[<hov 0>%a@]@]"
-            parameter Format.pp_print_text doc
-      | DefArg { parameter ; doc ; default } ->
-          Format.fprintf ppf "@[<v 2>@{<opt>%s _@} (default %s):@,@[<hov 0>%a@]@]"
-            parameter default Format.pp_print_text doc
+      | Arg { parameter ; placeholder ; doc } ->
+          Format.fprintf ppf "@[<v 2>@{<opt>%s <%s>@}:@,@[<hov 0>%a@]@]"
+            parameter placeholder Format.pp_print_text doc
+      | DefArg { parameter ; placeholder ; doc ; default } ->
+          Format.fprintf ppf "@[<v 2>@{<opt>%s <%s>@} (default %s):@,@[<hov 0>%a@]@]"
+            parameter placeholder default Format.pp_print_text doc
       | Switch { parameter ; doc } ->
           Format.fprintf ppf "@[<v 2>@{<opt>%s@}:@,@[<hov 0>%a@]@]"
             parameter Format.pp_print_text doc
@@ -553,10 +558,10 @@ let print_options_brief (type ctx) =
   let help_option :
     type a. Format.formatter -> (a, ctx) arg -> unit =
     fun ppf -> function
-      | DefArg { parameter } ->
-          Format.fprintf ppf "[@{<opt>%s _@}]" parameter
-      | Arg { parameter } ->
-          Format.fprintf ppf "[@{<opt>%s _@}]" parameter
+      | DefArg { parameter ; placeholder } ->
+          Format.fprintf ppf "[@{<opt>%s <%s>@}]" parameter placeholder
+      | Arg { parameter ; placeholder } ->
+          Format.fprintf ppf "[@{<opt>%s <%s>@}]" parameter placeholder
       | Switch { parameter } ->
           Format.fprintf ppf "[@{<opt>%s@}]" parameter
   in let rec help : type b. Format.formatter -> (b, ctx) args -> unit =
diff --git a/src/lib_stdlib_lwt/cli_entries.mli b/src/lib_stdlib_lwt/cli_entries.mli
index fca456f5a..420cd4675 100644
--- a/src/lib_stdlib_lwt/cli_entries.mli
+++ b/src/lib_stdlib_lwt/cli_entries.mli
@@ -28,13 +28,19 @@ type ('a, 'ctx) arg
 (** [arg ~doc ~parameter converter] creates an argument to a command.
     The [~parameter] argument should begin with a [-].
     If the argument is not provided, [None] is returned *)
-val arg : doc:string -> parameter:string ->
+val arg :
+  doc:string ->
+  parameter:string ->
+  placeholder:string ->
   ('p, 'ctx) parameter ->
   ('p option, 'ctx) arg
 
 (** Create an argument that will contain the [~default] value if it is not provided.
     see arg *)
-val default_arg : doc:string -> parameter:string ->
+val default_arg :
+  doc:string ->
+  parameter:string ->
+  placeholder:string ->
   default:string ->
   ('p, 'ctx) parameter ->
   ('p, 'ctx) arg
diff --git a/src/proto_alpha/lib_client/client_proto_args.ml b/src/proto_alpha/lib_client/client_proto_args.ml
index 03bd57efd..bc5c38199 100644
--- a/src/proto_alpha/lib_client/client_proto_args.ml
+++ b/src/proto_alpha/lib_client/client_proto_args.ml
@@ -61,6 +61,7 @@ let string_parameter =
 let init_arg =
   default_arg
     ~parameter:"-init"
+    ~placeholder:"data"
     ~doc:"The initial value of the contract's storage."
     ~default:"Unit"
     string_parameter
@@ -68,6 +69,7 @@ let init_arg =
 let arg_arg =
   default_arg
     ~parameter:"-arg"
+    ~placeholder:"data"
     ~doc:"The argument passed to the contract's script, if needed."
     ~default:"Unit"
     string_parameter
@@ -75,6 +77,7 @@ let arg_arg =
 let delegate_arg =
   arg
     ~parameter:"-delegate"
+    ~placeholder:"identity"
     ~doc:"Set the delegate of the contract.\
           Must be a known identity."
     string_parameter
@@ -82,6 +85,7 @@ let delegate_arg =
 let source_arg =
   arg
     ~parameter:"-source"
+    ~placeholder:"identity"
     ~doc:"Set the source of the bonds to be paid.\
           Must be a known identity."
     string_parameter
@@ -113,7 +117,7 @@ let tez_parameter param =
        | None -> fail (Bad_tez_arg (param, s)))
 
 let tez_arg ~default ~parameter ~doc =
-  default_arg ~parameter ~doc ~default (tez_parameter parameter)
+  default_arg ~parameter ~placeholder:"amount" ~doc ~default (tez_parameter parameter)
 
 let tez_param ~name ~desc next =
   Cli_entries.param
@@ -131,6 +135,7 @@ let fee_arg =
 let max_priority_arg =
   arg
     ~parameter:"-max-priority"
+    ~placeholder:"prio"
     ~doc:"Set the max_priority used when looking for baking slot."
     (parameter (fun _ s ->
          try return (int_of_string s)
@@ -144,6 +149,7 @@ let free_baking_switch =
 let endorsement_delay_arg =
   default_arg
     ~parameter:"-endorsement-delay"
+    ~placeholder:"seconds"
     ~doc:"Set the delay used before to endorse the current block."
     ~default:"15"
     (parameter (fun _ s ->
diff --git a/src/proto_genesis/lib_client/client_proto_main.ml b/src/proto_genesis/lib_client/client_proto_main.ml
index 025692588..e2040286f 100644
--- a/src/proto_genesis/lib_client/client_proto_main.ml
+++ b/src/proto_genesis/lib_client/client_proto_main.ml
@@ -50,6 +50,7 @@ let commands () =
     args1
       (arg
          ~parameter:"-timestamp"
+         ~placeholder:"date"
          ~doc:"Set the timestamp of the block (and initial time of the chain)"
          (parameter (fun _ t ->
               match (Time.of_notation t) with